The Demon was created by Jack Kirby. The title character, named Etrigan, is a demon from Hell who, despite his violent tendencies, usually finds himself allied to the forces of good. Etrigan, son of the demon Belial, is summoned by the wizard Merlin, his half-brother. Unable to gain the creature's secrets, he bonds the demon with Jason Blood, a knight in King Arthur's Camelot. This renders Jason immortal, though at times he considers this either a penance or a curse. He eventually becomes a prominent demonologist and settles in Gotham City.